C-clamp



Aug. 2, 1960 2,947,333

A. L. JOHNSON C-CLAMP Filed July 23, 1958 34 F|G.2 I llll 1H @I HH WWI. IHHHIIII ulu ml 'hl'l' 34 |4 |o ik INVENTOR 56 4 ALVINL. JOHNSON ATTORNEY States Patent Ofiic 2,947,333 Patented Aug. 2, 1960 C-CLAMI' Alvin L. Johnson, Worcester, Mass., assignor to Edgar G. Vaudreuil, Auburn, Mass.

Filed July 23, 1958, Ser. No. 750,375

2 Claims. (Cl. 144305) This invention relates to a new and improved O-clamp and the principal object of the invention resides in the provision of a clamp in the general nature of a C-clamp embodying means providing for substantially instantaneous and long range adjustment of a movable initial clamping member with relation to a short range movable anvil member together with means associated in cooperation therewith for providing the final clamping action of a work piece by means of said anvil member.

Further objects of the invention include the provision of a G-clamp having an anvil and means for very slightly moving the same relative to the main frame of the C- clamp, in combination with a freely movable clamping member to clamp a Work piece to said anvil, there being a cockable washer having resilient means normally maintaining the same in frictional engagement with said rod for holding the same in any position to which it is placed; in combination with means operated manually merely by pressing a thumb piece to release said cockable washer from said rod so that the same is quickly and easily movable as for instance by gravity to initially position a work piece against said anvil, whereupon said anvil is then movable to tight clamping position relative to said quickly movable member in order to tightly clamp a work piece.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. 1 is a view in elevation illustrating the invention, part being in section; I

Fig. 2 is a plan view looking in the direction of arrow 2 in Fig. 1;

Fig. 3 is an enlarged view showing the cockable washer action, parts being in section;- and Fig. 4 is a section on line 4--4 of Fig. 3, parts being broken away.

In carrying out the present invention, there is provided a main frame member including an elongated element 12 and a transverse or end member 14. The elongated member 12 may be made as shown as a partial portion of the main frame of the C-clamp and it has pivoted thereto adjacent its free end as at 16, as by a clevis, an anvil member generally indicated at 18. This anvil member makes up the remainder of the main body of the G-clamp and is provided with an anvil which forms one of the clamping members.

At its opposite end as at 22 the anvil member 18 is provided with some adjustment means such as a thumb screw 24 having an inner end 26 hearing in a recessed boss or the like 28 in order to pivot anvil member 18 in a clockwise direction about the pivot at 16.

In the example of the invention illustrated herein, the lateral portion 14 of the main frame member 10 is transversely slotted as indicated at 30 and this slot is continued vin a reduced form as at 32, see Fig. 3. This provides a loose pivoting mounting for the spaced legs or yoke indicated at 34 of a cockable washer generally indicated at 36. This cockable washer is provided with a circular hole at 38 for the sliding reception at right angles thereto of an elongated rod 40. It is to be noted that the slot 30 is considerably wider than the thickness of the cockable washer so that the latter is free to pivot slightly, the hole 38 being somewhat larger in diameter than the diameter of rod 40. The rod 40also passes through a pair of aligned apertures 42, 44 in the arms 46, 48 which are formed by slot 30 in the lateral portion 14 of main frame 10, and rod 40 is preferably provided with a pivoted foot 50 at the inner end thereof for clamping engagement with work piece W against the anvil 20 as shown in Fig. 1.

Slidably passing through arm 48 and the cockable washer 36 there is a pin 52. Pin 52 has an abutment 53, and is slidiugly receivable in a recess 54 in arm 46, see particularly Fig. 3. A spring 56 is interposed between the inner aspect of arm 46 and the cockable washer and is conveniently disposed in spiral form around the pin 52. Pin 52 may be provided with a finger or operating head 58 and the effect of this spring is to maintain the cockable Washer in the solid line position of Fig. 3 which as will be explained is in the locking position thereof with reference to the sliding rod 40.

In the operation of the device, the hand wheel 24 is first manipulated so as to bring the end 22 of the anvil member 18 into close proximity with elongated member 12. Then the operator may place his Work piece W on anvil 20, press the head 58 of pin 52 with his thumb. This action moves the cockable washer 36 from its cocked position to the dotted line position in Fig. 3 substantially at right angles to the rod 40 because of abutment 53. The aperture 38 being larger than the diameter of rod 40, the latter is released and falls by gravity, or may be pushed by proper manipulation, to an initial clamping position with respect to the Work piece W. Upon release of knob '58, spring 56 moves cockable washer 36 to its tilted or cocked relationship, i.e., out of normal or right angular position with respect to the axis of rod 40; whereupon the edges of the aperture 38 lightly, frictionally grasp or'grip rod 40 and hold it there in position so that it cannot be retracted accidentally.

The work piece is therefore lightly held in the position shown; and by a rotation or two of thumb piece 24 in the appropriate direction, anvil member 18 is rotated in a clockwise direction, see Fig. 1, to securely and solidly clamp the work piece W against the pivot foot 20.

To release the work piece, it is merely necessary to loosen hand wheel 24 a turn or two so that the anvil member 18 will be moved slightly in a counterclockwise direction. The rod 40 will be maintained in its position by the cockable washer until such time as the thumb piece 58 is again pressed to move the cockable washer to the dotted line position, see Fig. 3.

However, it will be seen that work pieces of widely diifering sizes may be almost instantly clamped by this construction for the reason that the rod 40 is instantly movable as long as the thumb piece 58 is pressed, but upon release of the thumb piece, the rod 40 is firmly held in whatever position it may happen to be and it is instantaneously movable between its ranges of adjustment merely by touching the thumb piece 58 to retract the washer to its non-holding or right angular relationship with respect to rod 40. The work piece cannot be accidentally unclamped by pressing thumb piece 58 accidentally; when the anvil member is in clamped relationship under influence of thumb piece 24, the cockable washer cannot be disturbed as it is held solidly in locking position by reason of the pressure of rod 40 thereon in an upward direction in Fig. 1. The only way to free the clamped work piece is to actuate thumb piece 24.

I claim:

1. A C-clamp comprising a main frame including a free-ended longitudinal member and a lateral end member therefor, a cross slot in said end member, said slot forming a pair of divided arms, said slot extending in- Wardly from the extreme end thereof toward the longitudinal member and terminating short thereof in an abutment, an elongated cockable washer in the slotbetween said divided arms, a yoke at one end of the washer, the legs of the yoke embracing said abutment, aligned apertures in the divided arms and cockable washer, a rod extending through said apertures, said rod having an inner, clamping end, the aperturein the Washer having a slightly greater diameter than the rod andtthe edge portions of the washer aperture frictionally gripping and holding the rod when the washer is cocked with respect to the rod and providing for free sliding motion of the rod when the washer is substantially at right angles to the rod, resilient means normallyholding the washer in cocked relation tothe rod, selective manually operated means to retract said resilient means to allow the washer to move to rod-free position, said means including a pin, means on the pin to engage the washer at one end, means slidably mounting the pin, the other end of the pin being exposed for actuation by a finger of the operator to retract the washer from rod holding position against the action of the spring, said main frame also including an anvil member, means pivotally connecting the latter to the longitudinal member adjacent the free end thereof, an anvil on the anvil member, said anvil being generally aligned with the rod axially thereof, adjustable means on the anvil member in cooperative relationship with the longitudinal member to cause pivotal action of the anvil member thereon in a direction to move the anvil toward the clamping end of the rod, said adjustable means being located at a point remote from the pivoting means, said rod being releasable from the coekable washer and freely slidable to lightly clamp a workpiece onlthe anvil, and the adjustable means being operative to more tightly clamp the workpiece against the clamping end of the rod while the cockable washer holds the rod against retraction.

2. The C-c1amp of claim 1 wherein said adjustable means comprises an element movable transversely of the anvil member to press on the longitudinal frame member, an c desmeans 10 mor t e lemen 

